Adaptive Signal Control for Overflow Prevention at Isolated Intersections Based on Fuzzy Control

Abstract

Nonrecurrent congestion on urban roads may cause overflow, possibly leading to gridlock at intersections. Signal control is one of the most important measures to prevent such phenomena. For nonrecurrent congestion with uncertain bottleneck capacity, however, existing signal control methods have mainly adopted the strategy of cutting off the green signal of the overflow movement while the release priority of green time has not been considered. Consequently, the green time allocated to overflow movements is too long, aggravating overflow and congestion. Therefore, a signal control method is proposed to prevent overflow caused by uncertain bottleneck capacity. The proposed method extends existing real-time adaptive signal control to explicitly consider the risk of queue spillover. When an overflow risk is detected, the green times of overflow movements will be reassigned using fuzzy control to determine the release priority depending on the queue length and red time. Numerical studies were conducted for two scenarios with different downstream bottleneck capacities. The results demonstrate that the proposed method not only outperforms existing methods in respect of intersection efficiency but also reduces the risk of overflow. The proposed method achieves a 27.7% to 33.8% reduction in the maximum queue length of overflow movements compared with a traditional adaptive signal control method and a 10.9% to 11.0% decrease compared with a modified signal control method with a cutting-off strategy. The sensitivity analysis indicates that the average delay resulting from the proposed method is 51.1% and 18.0% less than the delays resulting from the traditional and modified methods, respectively.

A two‐stage robust optimal traffic signal control with reversible lane for isolated intersections

“…The traffic signal timing plan optimization procedure employed typically takes on one of two forms: fixed timing plans (off-line) and adaptive signal controls (on-line), with their own advantages and disadvantages in practice. Yao et al [32] proposed an adaptive signal control method based on fuzzy control, which extends existing real-time adaptive signal control to explicitly consider the risk of queue spillover. The integrated optimization of all parameters requires expensive calculations, which are more suitable for offline methods.…”

“…Yao et al. [32] proposed an adaptive signal control method based on fuzzy control, which extends existing real‐time adaptive signal control to explicitly consider the risk of queue spillover. The integrated optimization of all parameters requires expensive calculations, which are more suitable for offline methods.…”

An emergency vehicle traffic signal preemption system considering queue spillbacks along routes and negative impacts on non‐priority traffic

“…Queue spillback is a critical issue in traffic signal control operations. Many studies have addressed this issue, focusing on preventing spillbacks at isolated intersections [35], coordinated controlled arterials [36][37][38][39], and intersections connected to freeway on-ramps [40,41]. Despite efforts by traffic engineers and researchers to mitigate spillbacks through signal plan design, they can still occur during peak hours in urban areas, possibly due to excessive traffic volumes.…”